Solar panels have become cheaper and more efficient in recent years, but they are far from a universal solution, even in sunny regions. One reason is that a typical solar photovoltaic (PV) installation is still beyond the budget of many people. The average pricing for a 5kW residential PV system completed in 2014 varied from $11,000 in Germany to $16,450 in the USA. [1, 2] Roughly half of that amount concerns the installation costs. 
A second obstacle for solar power is that not everybody lives in a single-family dwelling with access to a private roof. Those who reside in apartment buildings have little chance of harvesting solar power with a conventional roof-mounted system. Furthermore, in apartment buildings, the roof would quickly become too crowded to cover the electricity use of all residents, a problem that grows larger the more floors there are in a building. Lastly, a typical solar installation is problematic when you’re renting a place, whether it’s a house or an apartment.
These conditions allow me to get through the winter without a heating system, relying only on solar heat and thermal underclothing. Hot water is supplied by a solar boiler, which was installed by the landlord. Clothes are dried on the balcony. While tinkering with solar panels for an art project, I got an idea: with the sun already powering so much of my living space, wouldn’t it also be possible to harvest solar power from the window sills and the balcony and take my apartment off the electricity grid? Such a PV installation would solve my problems:
- I don’t need access to the roof.
- I can install the system myself, which makes it much cheaper.
- I can take the solar installation with me if I move to another place.
Obviously, the big question is whether or not such an unconventional solar system could generate the necessary electricity. As a first experiment, I decided to power my 10 m2 home office with solar panels placed on the 2.8 m long window ledge that runs along the windows of the office and the adjacent bedroom.
read more at: http://www.lowtechmagazine.com/2016/05/how-to-go-off-grid-in-your-apartment.html
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